The present invention relates to a biosensor device.
Recently, small ion sensors and semiconductor biosensor devices using them have been developed using a semiconductor manufacturing technique. A semiconductor biosensor device has a size of, e.g., about 0.6 mm.times.0.3 mm .times.4 mm, and the sensing region of the probe is located within 1 mm from its distal end. Therefore, measurement can be performed even if a total amount of liquid to be measured is 30 .mu.l or less.
Heretofore, a chemical substance in a solution was sensed by immersing a sensor of this type. The measured result was not reliable due to a poor reproducibility. If the amount of the solution including the substance to be sensed is small, the sensed output is not reliable at all.